Gosh, ‘hidden’ climate change may threaten eelgrass meadows

From the University of Gothenburg , the stuff that keeps some people awake at night. A question; why should we care? And, why should we take any of this seriously when you do things like “We raised the water temperature in miniature ecosystems containing eelgrass meadows, while simultaneously bubbling with carbon-dioxide.” when that “bubbling” would not happen naturally?

Hidden effects of climate change may threaten eelgrass meadows

Some research has shown that the effects of changes in the climate may be weak or even non-existent. This makes it easy to conclude that climate change will ultimately have less impact than previous warnings have predicted. But it could also be explained as direct and indirect effects cancelling each other out, as scientists from the University of Gothenburg, Sweden, show in a paper recently published in PNAS, the esteemed US scientific journal.

To investigate how different climate impacts interact, an experiment was conducted at Kristineberg Marine Research Station.

“We raised the water temperature in miniature ecosystems containing eelgrass meadows, while simultaneously bubbling with carbon-dioxide. This allowed us to simulate a future climate scenario, characterized by both warmer waters and ocean acidification”, explains researcher Christian Alsterberg.

Eelgrass meadows grow in shallow coastal waters and are among the most productive ecosystems in the sea. These meadows are now threatened, not only by climate change but also by overfishing and eutrophication.

“By studying eelgrass meadows on a ecosystem level, we were able to observe how plants and animals interact under changing climatic conditions. This also allowed us to measure the indirect effects, meaning the effects of climate change on an animal or a plant mediated through another organism.”

For example, the metabolism of many crustaceans that live in eelgrass meadows increases when the water temperature rises. This in turn means they need to eat more algae and may consequently graze it more efficiently. At the same time, the growth of benthic microalgae on the sediment surface in the eelgrass meadows will be more vigorous.

Using statistical methods that separates direct and indirect effects, the researchers were able to discern how higher water temperature combined with ocean acidification affects not just individual species but also interactions between species in the ecosystem.

The researchers found that the effects are largely determined by the presence or absence of different fauna, primarily small algae-eating crustaceans. The net effect of changes in temperature and ocean acidification on benthic microalgae is non-existent if there are crustaceans in the ecosystem. But in the absence of crustaceans, the amount of benthic algae is largely controlled by positive and negative direct and indirect effects of higher temperatures and acidification.

The results showed that, without small algae-eating crustaceans in the eelgrass meadows, climate change could pose a much greater threat to their survival.

“The experiment also taught us the importance of investigating climate change using several different approaches, in order to fully understand its effects and to predict future impacts”, says Christian Alsterberg.

These experiments are great.
Here are some suggestions to more:
– Check how much a frog can stay in boiling water.
– Examine the effects of 500000 PPM of CO2 on zebras.
– Model the results of 0% Oxygen on beetles
….
The possibilities are endless, and so shall be the finance.
One point to remember: Always refer to these “researches” in context of AGW.
Good luck.

I wonder why so timid in setting their conditions? I’ll bet that if they bubbled Hydrogen Sulfide through the system it would REALLY have had an impact on the eelgrass! (what with it liking to turn into sulfuric acid when it hits water and that kind of thing)

And just imagine if they had pumped in some hot magma? Come on guys, if you want to make news, swing for the fences!

Holy Hannah. This work is the product of meme-recital. An uncritical spouting of effects of an artificially acidified ocean…whose pH is still above 7 by a substantial margin. They mention nothing of diurnal changes in water temperature, from tides, sunlight or stagnation. Crustaceans and eel grass survive this quite nicely, you silly people. Perhaps take note of the fact. Try places like the Bay of Fundy, with its seasons, its huge tidal range, and its two-stage volume distribution consisting of the inner Minas Basin and the outer, larger, and colder, bay; the movement at spring tide of eight cubic kilometers of water and the huge suspended sediment load it produces…but all the while, the sandpipers come back year after year to gorge on the crustaceans who, when force-fed a lab full of bubbles (simulated crustacean flatulence, no doubt), would sink perilously into decline while gorging on tax dollars.

I copied the following statement directly from the PDF file from the link posted above:

‘Here, we experimentally tested whether consumers can mediate the effects of warming and acidification on primary producers in seagrass ecosystems, one of the most productive, and threatened, coastal ecosystems on earth (24).’

Now, I certainly hope that the researchers aren’t talking about the “consumers” that will cease to exist (and partly have ceased to exist) in the economies of the “ecosystems” (i.e. countries) that have embraced climate change legislation,

On a different note; I’m well past the stage where one begins to need reading glasses, and I’m working from an I-phone so I’m looking at a small screen, plus I scanned the 6 pages of that PDF file fairly quickly, but I was not able to find out precisely what temperature it was that they raised the eelgrass environment to. Maybe it was plain as day and I missed it. I would think so. But is it possible that it wasn’t stated?

Not the eelgrass! Lord Gawd please, not the eelgrass! I made peace with my evolutionary destiny, that my great great great great great grandkids will be hobbits. I shed my tears for the working girls. I shivered with fear thinking about the giant crustaceans. But this is simply too much to bear. The eelgrass!
/sarc

Perhaps before criticizing the bubbling it would be good to actually read how it was done? It’s not like they had bubbles seeping throughout the area(as one commenter already suggested). It is one thing to criticize actual experimental design. It is quite another to just say “bubbles don’t happen naturally” and skip over what they actually did.
REPLY: no matter how you look at the experimental design, it isn’t how the ocean actually works. We’ve had a number of studies like this where they try to simulate ocean conditions, but the simulation doesn’t reflect the real world. I don’t think this one does either. – Anthony

A group of illustrious intellectual scientists do a study looking at the effect of increased temperature and carbon dioxide on a shoreline ecosystem. . . .and somehow in their published results never manage to state the temperature of the two systems. . . .or the amount of carbon dioxide introduced into the second system?

Unless I’m really missing something here, the only information about temperatures they used two twenty gallon tanks, and one tank was hotter by four degrees than the other, which was at an “ambient” temperature, whatever that was.

“And, why should we take any of this seriously when you do things like “We raised the water temperature in miniature ecosystems containing eelgrass meadows, while simultaneously bubbling with carbon-dioxide.” when that “bubbling” would not happen naturally?” -Anthony

And why should we take your claim seriously when you plainly didn’t read the paper?

DID you read the paper? Can you explain how and where bubbling was done in relation to the measured environment? I think the suggestion that you make with your question is that they have bubbles running IN the measured grass beds. Clearly, at least one of your commenters also thought this. The paper makes it clear that this is not the case.

“We raised the water temperature in miniature ecosystems containing eelgrass meadows, while simultaneously bubbling with carbon-dioxide. This allowed us to simulate a future climate scenario, characterized by both warmer waters and ocean acidification”, explains researcher Christian Alsterberg.

Just the other day on the BBC there was a report on a study about some cockroaches having an aversion to glucose. Glucose is sometimes used by pest control on food to mask the poison. It was noticed by the same team that 20 years ago some pest controllers were failing to get rid of roaches. What this shows that some life can adapt quickly, but not that quick.

“The results showed that, without small algae-eating crustaceans in the eelgrass meadows, climate change could pose a much greater threat to their survival.

In future hard hitting reports:
Whether a reduction in dung beetles due to anthropogenic climate change puts the entire world at risk of becoming one huge dung pile?
Whether an absence of ants due to anthropogenic climate change poses a risk to anteater survival?
Whether a reduction in bamboo due to anthropogenic climate change threatens the adorable panda bear?
Whether reduced snow due to anthropogenic climate change endangers Frosty?

My point being that without something eating the algae the eelgrass meadow is doomed to be … wait for it … overgrown with algae. I’m with Ben Wilson, it sounds like a middle school science project.

The researchers were trying to simulate the IPCC’s scenario A1F1 aka “business as usual”, which “projects” a temperature increase of as much as 7 degrees C by 2100. That’s why they dropped pH from 8.1 down to 7.7 (!) and raised water temp by a whopping 4 degrees C. As Anthony points out, this is “reality” only in the virtual world of Playstation climatology. Back in the real world, while so-called “greenhouse gases” are increasing roughly in line with scenario A1F1, so-called “global average temperature” is tracking well below A1F1 projections.

All is not lost, however. These results may be of interest to eelgrass aquarium hobbyists and commercial coastal crustacean culturists. :-)

Just a few comment after reading the explanation of how their method in their paper.

On the plus side they pumped water from the ocean into a tank system where it’s temperature was either unadjusted or raised 4 degrees C, the adjustment was done continuously by a computer controlled system, after adjustment the water was fed to the experiments. So natural variations in temperature due to time of day and season were mirrored.

On the plus and minus side we have the pH adjustment issue. The pH was also either adjusted to ~8.1 or ~7.7 by controlled bubbling of either ambient air or CO2 enriched air, after adjustment the water was fed to the experiments. So the bubbling issue really was just how they adjusted pH, another more natural method could have been used but the result would have been the same. I do question whether the continuous adjustment of the pH mirrored natural variations in pH over time due to tides and rain.

On the minus side I see the following issues.
-The experiment was run in 30 liter buckets. That size seems very small to model an ecosystem.
-8 mixes of system parameters with varying temp, pH and herbivores were replicated 5 times. 5 sample runs seems like a pretty small sample size and runs with no herbivores seems pointless.
-The experiment was only run for 5 weeks from July through August. That seems like a very short run time and it only simulated 1/10 of the year.
-The 4 degree C heating was taken from the IPCC A1FI prediction for 2100. With the species involved an 90 year time span for the 4 degree change to occur would allow for some natural selection and habitat adjustment by all the species involved rather than a sudden jump from 2010 conditions to 2100 conditions.
-The experiment only involved one species of eel grass, one species of added green algae and three species of herbivorous gastropod/crustacean. Eel grass beds are rich ecosystems with fish, predatory crustaceans and see birds, leaving these other factors out of the system brings into doubt the validity of the results.

If I was running experiments to show how higher atmospheric levels will impact ocean environments, I would place the test tanks in rooms with the higher CO2 levels I was trying to test for. Bubbling in CO2 only gives good information about what happens when one bubbles in CO2.
It is not difficult for horticulturalists to build and maintain greenhouses which impose increased CO2 on the plants in the greenhouse. I wonder why the experimenters in this case used such tiny tanks, and did not use CO2 rooms.

“Using statistical methods that separates direct and indirect effects,” reveals the BS factor. Statistic methods reveal correlations, but not causation. They are mathematically unable to distinguish between “direct” and “indirect” effects because they are unable to even identify effects or causes.
The sad truth of statistics is that those who do not carefully study the mathematical basis for their use (and the assumptions involved) are extremely prone to self-delusion through mis-assigning significance.

The idea that the level of CO2 in the ocean is going to research the same levels as if you bubble up water with CO2 is absurd.

This whole experiment reminds me of an experiment I did when I had fish aquarium as a hobby. In a magazine I read about how you could improve plant growth using CO2.
So, I did. I filled a bottle with water, yeast and sugar and arrange so that any gas from the bottle would bubble up in the aquarium. Then I waited.
After a while when the process had started I return and found that a few of my fish have died and the rest of them were gasping for air.
I quickly realized that the CO2 has pushed out too much of the oxygen from the water.
I then reduced the amount of released CO2 to safe levels into the water and let it run for a week or so, and the plants in the aquarium got a big boost.
The lesson from this experiment is that if feed water with too much CO2 the fish are going to die, not by acidification, but by oxygen deprivation.

They just showed that you have to test the eco-system as a whole, not as individual components.

Test the eel grass by itself for the effects of global warming, and you get a slight improvement in growth. Test it with the algae added and you have a disaster. Add the crustaceans and the system compensates and is stable.

“The researchers found that the effects are largely determined by the presence or absence of different fauna, primarily small algae-eating crustaceans. The net effect of changes in temperature and ocean acidification on benthic microalgae is non-existent if there are crustaceans in the ecosystem. But in the absence of crustaceans […]”

They have drawn the wrong conclusion. Theprincipal factor was clearly the presence or absence of crustaceans.

“The researchers found that the effects are largely determined by the presence or absence of different fauna, primarily small algae-eating crustaceans. The net effect of changes in temperature and ocean acidification on benthic microalgae is non-existent if there are crustaceans in the ecosystem. But in the absence of crustaceans […]”

They have drawn the wrong conclusion. Theprincipal factor was clearly the presence or absence of crustaceans.
###

Yup, that about sums it up. BTW, for this experiment to be even close to valid, the aquariums would need to be established for at least 6 months, though a year would be much better, and the experiment would need to run at least 6 months. As far as I can tell, the aquariums never had the chance to reach biological stability. This really is on a loosing HS science fair project level.

OK, but we should also be asking why eel grass grows in shallow waters?
Because they will be nearer to the light for photosynthesis. (Obvious)
Because photosynthesis rapidly removes dissolved CO2 and upper surface waters, even warm ones, quickly replenish this loss from the atmosphere.(remember temperature is the most important criteria for gas dissolution in water, the higher the temperature the less gas dissolves).

When in the RAF I used to visit a small Indian Ocean island in the Adu Attol, RAF Gan. The shallow areas in parts of this island were rich in eel grass growing in temperatures of 25-30C. It seems eel grass has little trouble with temperature extremes all it really wants is abundant sun and CO2.

I really wish that individuals would get their acid- base chemistry straight. An acid-base system is not dipolar like electrical charge. That is, if a solution is less alkaline, it is not more acidic. This is because the neutral state must be considered. You can lower the pH of an alkaline solution solution by simply adding water. It is not more acidic. It is simply less alkaline. In fact, it would never become acidic. Oceans are gigantic buffer systems. At a CO2 level of 5000 ppm (this was the level of CO2 when corals formed), global temperature was the same as it is today and ocean pH was around 7.6, still basic.